ISO 18425-2013 PDF

Full title and description

Space data and information transfer systems — Spacecraft Onboard Interface Services — Subnetwork Packet Service (ISO 18425:2013). This International Standard specifies the services and service interfaces for the SOIS (Spacecraft Onboard Interface Services) Subnetwork Packet Service used on spacecraft onboard subnetworks; it defines the service semantics and interfaces but does not prescribe link‑level implementation methods.

Abstract

ISO 18425:2013 is part of the SOIS family of documents and defines the Subnetwork Packet Service: the functional service definitions and interfaces an onboard subnetwork must provide for packetized data transfer. The standard is intended to be used together with the SOIS Green Book and leaves link‑specific protocol details to mission/agency/CCSDS documents.

General information

• Status: Published; reviewed and confirmed (remains current as reviewed by ISO periodic review).
• Publication date: 29 May 2013 (ISO edition 1, 2013-06).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 49.140 (Space systems and operations).
• Edition / version: Edition 1 (2013).
• Number of pages: 27 pages.

Scope

Specifies the service definitions and externally visible service interfaces of the SOIS Subnetwork Packet Service for spacecraft onboard subnetworks. The scope is limited to specifying the service (what is provided) and not the particular methods or physical/link protocols used to implement it on different onboard data links; protocols providing the service are expected to be documented separately (by missions, agencies or CCSDS). The standard conforms to the principles of the SOIS Green Book and is meant to be applied alongside that guidance.

Key topics and requirements

• Definitions of Subnetwork Packet Service functions and expected behaviors.
• Service interface descriptions for interaction between onboard software and subnetwork services.
• Requirements for packet delivery, addressing, service primitives and error/exception handling at the service level.
• Clarification that link‑level protocols and physical implementations are out of scope and must be defined separately for each link.
• Conformance with SOIS Green Book principles and alignment with relevant CCSDS material.

Typical use and users

Used by spacecraft systems and avionics engineers, mission architects, onboard software developers, spacecraft subcontractors and agencies implementing or integrating SOIS-compliant onboard communications. Typical applications include defining service-level interfaces for onboard packet switching, message routing between subsystems, and specifying the service contract between software components and the onboard subnetwork layer.

Related standards

Part of the ISO SOIS family and intended to be applied with the SOIS Green Book. It is linked to CCSDS publications that document link‑specific protocols and has been adopted from or aligned with CCSDS material (see CCSDS reference documents such as CCSDS publications on subnetwork services). Related ISO/CCSDS references include other SOIS documents and the mission operations reference model (for example ISO 18201 is within the same topical family).

Keywords

SOIS, Subnetwork Packet Service, spacecraft onboard interface, packet service, CCSDS, onboard communications, service interface, avionics, space data transfer.

FAQ

Q: What is this standard?

A: ISO 18425:2013 defines the Spacecraft Onboard Interface Services Subnetwork Packet Service — the service-level definitions and interfaces used for packet transfer over spacecraft onboard subnetworks.

Q: What does it cover?

A: It covers service semantics and externally visible service interfaces for the Subnetwork Packet Service. It does not define physical links or link-layer protocols; those are documented separately for each link or mission.

Q: Who typically uses it?

A: Spacecraft systems engineers, onboard software developers, mission designers, space agencies and suppliers integrating SOIS-compliant subsystems.

Q: Is it current or superseded?

A: Published in 2013 (Edition 1) and reviewed/confirmed by ISO in a subsequent periodic review (status shown as published/confirmed by ISO); users should check the ISO catalogue or national standards body for the absolute latest status before procurement or formal citation.

Q: Is it part of a series?

A: Yes — it is part of the SOIS (Spacecraft Onboard Interface Services) family of standards and is intended to be used alongside the SOIS Green Book and related CCSDS/ISO SOIS documents.

Q: What are the key keywords?

A: SOIS, Subnetwork Packet Service, spacecraft, onboard interface, packet, CCSDS, service interface.